Shoichi Ichimura

Effect of walking exercise on bone metabolism in postmenopausal women with osteopenia/osteoporosis

The purpose of this prospective study was to determine whether moderate walking exercise in postmenopausal women with osteopenia/osteoporosis would affect bone metabolism. Fifty postmenopausal women, aged 49–75 years, with osteopenia/osteoporosis were recruited: 32 women entered the exercise program (the exercise group) and 18 served as controls (the control group). The exercise consisted of daily outdoor walking, the intensity of which was 50% of maximum oxygen consumption, with a duration of at least 1 h with more than 8000 steps, at a frequency of 4 days a week, over a 12-month period. Lumbar (L2–L4) bone mineral density (BMD) was measured at the baseline and every 6 months with dual-energy X-ray absorptiometry (DXA) in both groups. Serum bone-specific alkaline phosphatase (BAP) and urinary cross-linked N-terminal telopeptides of type I collagen (NTX) levels were measured at baseline and at months 1, 3, 6, 9, and 12 by EIA and ELISA, respectively, in the exercise group, and urinary NTX level was measured at the baseline and every 6 months in the control group. There were no significant differences in baseline characteristics including age, height, body weight, bone mass index, years since menopause, lumbar BMD, and urinary NTX level between the two groups. Although no significant changes were observed in lumbar BMD and the urinary NTX level in the control group, lumbar BMD in the exercise group was increased as compared with the control group, but was sustained from the baseline. In the exercise group, the urinary NTX level rapidly responded to walking exercise from month 3, and this reduction was sustained until month 12, followed by reduction in the serum BAP level. A moderately negative correlation was found between the percent change in the urinary NTX level at month 3 and that in lumbar BMD at month 12 in the exercise group. This study clearly demonstrates that the mechanism for the positive response of lumbar BMD to moderate walking exercise in postmenopausal women with osteopenia/osteoporosis appears to be the suppression of bone turnover, and that an early change in the urinary NTX level may be useful to predict the long-term response of increasing lumbar BMD to exercise, although its efficacy for lumbar BMD may be quite modest.

Effects of treadmill exercise on bone mass, bone metabolism, and calciotropic hormones in young growing rats.

The aim of the present study was to examine the effects of exercise on bone mass, bone metabolism, and calciotropic hormones in young growing rats. Twenty 6-week-old female Wistar rats were randomized into the following four groups with 5 animals each: 7 weeks of exercise, 7 weeks of sedentary control, 11 weeks of exercise, and 11 weeks of sedentary control. The exercise regimen consisted of running on a treadmill at 25 m/min for 1 h each day on 5 days a week. After each period of exercise, the bone mineral content (BMC) of the tibia and fifth lumbar spine was measured by dual-energy X-ray absorptiometry, using a Lunar DPX-L instrument. The femoral length and levels of bone markers and calciotropic hormones were also assessed. Seven and 11 weeks of exercise increased the serum osteocalcin and 1,25-dihydroxyvitamin D3 levels, and decreased the serum parathyroid level. Seven weeks of exercise decreased the urinary deoxypyridinoline level, and 11 weeks of exercise increased the serum alkaline phosphatase level and decreased the serum tartrate-resistant acid phosphatase level. As a result, 7 and 11 weeks of exercise increased the femoral length and tibial BMC, but did not alter the lumbar BMC. The present study demonstrates that treadmill exercise stimulates bone formation and suppresses bone resorption, increases the serum 1,25-dihydroxyvitamin D3 level, and decreases the serum parathyroid hormone level, resulting in an increase in bone mass with stimulation of longitudinal bone growth, especially at weight-bearing sites, in young growing rats. Further studies with long-term exercise may be needed to obtain a positive effect on the lumbar BMC.

Radiographic predictors for the development of myelopathy in patients with ossification of the posterior longitudinal ligament: a multicenter cohort study.

Study Design. A multicenter cohort study was performed retrospectively. Objective. To identify radiographic predictors for the development of myelopathy in patients with ossification of the posterior longitudinal ligaments (OPLL). Summary of Background Data. The pathomechanism of myelopathy in the OPLL remains unknown. Some patients with large OPLL have not exhibited myelopathy for a long periods of time. Predicting the course of future neurologic deterioration in asyptomatic patients with OPLL is difficult at their initial visit. Methods. A total of 156 OPLL patients from 16 spine institutes with an average of 10.3 years of follow-up were reviewed. Subjects underwent a plain roentgenogram, computed tomography (CT), and magnetic resonance imaging of the cervical spine during the follow-up. The trauma history of the cervical spine, maximum percentage of spinal canal stenosis in a plain roentgenogram and CT, range of motion of the cervical spine, and axial ossified pattern in magnetic resonance imaging or CT were reviewed in relation to the existence of myelopathy. Results. All 39 patients with greater than 60% spinal canal stenosis on the plain roentgenogram exhibited myelopathy. Of 117 patients with less than 60% spinal canal stenosis, 57 (49%) patients exhibited myelopathy. The range of motion of the cervical spine was significantly larger in patients with myelopathy than in those of without it. The axial ossified pattern could be classified into 2 types: a central type and a lateral deviated type. The incidence of myelopathy in patients with less than 60% spinal canal stenosis was significantly higher in the lateral deviated-type group than in the central-type group. Fifteen patients of 156 subjects developed trauma-induced myelopathy. Of the 15 patients, 13 had mixed-type OPLL and 2 had segmental-type OPLL. Conclusion. Static and dynamic factors were related to the development of myelopathy in OPLL.

Comparative effects of vitamin K and vitamin D supplementation on prevention of osteopenia in calcium-deficient young rats

The aim of this study was to clarify the difference in the effects of vitamin K and vitamin D supplementation on the development of osteopenia in young rats under mild calcium deficiency. Sixty female Sprague-Dawley rats, 6 weeks of age, were randomized by stratified weight method into six groups with 10 rats in each group: baseline control, 0.5% (normal) calcium diet, 0.1% (low) calcium diet, 0.1% calcium diet + vitamin K (30 mg/100 g, food intake), 0.1% calcium diet + vitamin D (25 microg/100 g, food intake), and 0.1% calcium diet + K + D. After 10 weeks of feeding, serum calcium, 25-hydroxyvitamin D(3) [25 (OH) D(3)], 1,25-dihydroxyvitamin D(3) [1,25 (OH)(2) D(3)], and parathyroid hormone (PTH) levels were measured, and intestinal calcium absorption and renal calcium reabsorption were evaluated. Bone histomorphometric analyses were performed on cortical bone of the tibial shaft and cancellous bone of the proximal tibia. Calcium deficiency induced hypocalcemia, increased serum PTH and 1,25 (OH)(2) D(3) levels with decreased serum 25 (OH) D(3) level, stimulated intestinal calcium absorption and renal calcium reabsorption, and reduced maturation-related cortical bone gain as a result of decreased periosteal bone gain and enlarged marrow cavity but did not significantly influence maturation-related cancellous bone gain. Vitamin K supplementation in calcium-deficient rats stimulated renal calcium reabsorption, retarded the abnormal elevation of serum PTH level, increased maturation-related cancellous bone gain, and retarded the reduction in maturation-related cortical bone gain. On the other hand, vitamin D supplementation in calcium-deficient rats stimulated intestinal calcium absorption via increased serum 1,25 (OH)(2) D(3) level with prevention of the abnormal elevation of serum PTH level, prevented hypocalcemia, reduced the maturation-related cancellous bone gain, and prevented the reduction in periosteal bone gain and enhanced enlargement of the marrow cavity with no significant effect on the reduction in maturation-related cortical bone gain. However, no synergistic effect of vitamin K and vitamin D on intestinal calcium absorption, renal calcium reabsorption, and cancellous and cortical bone mass was found. This study shows the differential effects of vitamin K and vitamin D supplementation on the development of osteopenia in young rats under mild calcium deficiency. Vitamin K supplementation stimulates renal calcium reabsorption, increases maturation-related cancellous bone gain, and retards the reduction in maturation-related cortical bone gain, whereas vitamin D supplementation stimulates intestinal calcium absorption and prevents the reduction in maturation-related periosteal bone gain by inducing accumulation of calcium from cancellous and endocortical bone.

Skeletal unloading induces a full-thickness patellar cartilage defect with increase of urinary collagen II CTx degradation marker in growing rats

Mechanical stress plays an important role in tissue morphogenesis and extracellular matrix metabolism. However, little is known about the effects of reduced loading without restriction of joint motion on the patella. We investigated the effects of long-term skeletal unloading on patellar cartilage and subchondral bone and systemic collagen II metabolism. Nine-week-old male F344/N rats (n=128) were randomly divided into two groups: caged control (C) and tail suspended (TS). Hindlimbs of the TS rats were subjected to unloading for up to 12 weeks. Sequential changes in the patellar cartilage and subchondral bone were analyzed macroscopically, by pathological findings and histomorphologically. All animals received double tidemark fluorochrome labeling prior to sacrifice. Glycosaminoglycan (GAG) content in patellar cartilage, cross-linked C-telopeptide of type II collagen (CTx-II) in 24-h urine and type II procollagen-C-peptide (pCol-II-C) in sera were also measured by DMB assay, ELISA and EIA, respectively. In the TS group, GAG content was significantly reduced only during the first 3 weeks. No further significant decrease was found. Alkaline phosphatase (ALP) activity was increased, especially at the deep zone. Tidemark mineral apposition rate (MAR) was temporally increased, which resulted in an increase in the ratio of calcified cartilage to the entire cartilage. In the medial part, in addition, thickness of the entire cartilage was decreased by temporal acceleration of subchondral ossification advancement and, in the medial margin, a full-thickness cartilage defect was revealed in 88.6% of TS rats. However, the remaining articular surface was free from fibrillation. While urinary CTx-II was significantly increased during the experimental periods, serum pCol-II-C was significantly decreased at the early phase. There were significant correlations between the urinary CTx-II levels and tidemark MAR. Our results provided evidence that skeletal unloading increased ALP activity at the deep zone and temporally accelerated tidemark advancement associated with a decrease in proteoglycan content. In addition, skeletal unloading temporally accelerated subchondral ossification advancement in the medial part of the patella and finally induced a full-thickness patellar cartilage defect without any fibrillation at the remaining articular surface by additional subchondral bone modeling and possible retarded cartilage growth, which was through a different mechanism than overloading.

Posterior spinal fusion for lumbar degenerative diseases using the Crock-Yamagishi (C-Y) spinal fixation system.

Although many transpedicular screw systems have been developed and have undergone wide clinical use, experience with semirigid transpedicular systems has rarely been reported. We evaluated the efficacy and safety of the Crock-Yamagishi (C-Y) system for posterior spinal fusion in lumbar degenerative diseases. The outcomes for 26 patients (14 men, 12 women) with lumbar degenerative diseases who underwent posterior spinal fusion using the C-Y system were analyzed (posterior lumbar interbody fusion (PLIF), 11 patients; posterolateral fusion (PLF), 14; and facet fusion (FF), 1. Symptoms were evaluated using the Japanese Orthopaedic Association Assessment of Treatment for Low Back Pain (JOA score). Preoperative scores ranged from -1 to 23 points (mean, 12.8), while postoperative scores ranged from 19 to 29 points (mean, 26.4). Degree of recovery ranged from 23.1% to 100% (mean, 83.2%). Overall fusion rate was 96.2% (25/26). Neither breakage nor loosening of implants was observed radiographically. Intra- and postoperative complications included one case of transient L5 nerve root palsy attributable to surgical technique, and one deep postoperative infection. The C-Y system, categorized as semirigid, is effective when used with one- or two-level PLIF or PLF for lumbar degenerative disorders, grade I to II spondylolisthesis, and failed back syndrome.

Endodermal cyst of the cervical spine treated by an anterior approach for resection and shunting

In most reported cases, a posterior approach to the cervical spine was used to remove an endodermal cyst or to place a shunt for cyst drainage. The authors performed partial excision, shunt insertion, and anterior spinal fusion in a patient with endodermal cyst of the cervical spine. Symptoms resolved after surgery and magnetic resonance images indicated morphologic restoration of the spinal cord.

Surgical site infection in malignant soft tissue tumors

BackgroundPostoperative wound complications, including surgical site infections, which frequently occur in the course of management of musculoskeletal sarcomas, sometimes necessitate repeat surgeries, including amputation, and may result in a prolonged healing time, prolonged hospital stay, or fatal outcome. A comprehensive understanding of surgical site infections associated with specific diseases is needed to reduce the risk.MethodsThis series comprised 84 patients with malignant soft tissue tumors treated at our institute. The occurrence rate, management modality and clinical course of surgical site infections, impact of surgical site infections on the length of hospitalization, risk factors for the development of surgical site infections, and the impact of surgical site infections on the oncological outcomes were analyzed. Surgical site infection was defined according to Centers for Disease Control and Prevention guidelines.ResultsSurgical site infections occurred in 7 cases (8.3%). Although successful clinical cure was achieved in all cases, surgical site infection was identified as one of the independent risk factors for prolongation of hospitalization. Both univariate and multivariate analyses identified larger intraoperative blood loss and a trunk location as risk factors associated with deep infections. No association was detected between age, tumor grade, chemotherapy, tumor volume, or plastic surgery and the risk of surgical site infections. Although the differences were not statistically significant, patients with surgical site infections showed worse oncological outcomes in terms of local recurrence and total survival.ConclusionThe incidence rate of surgical site infection was larger than that associated with conventional orthopedic surgeries, such as osteosynthesis, spine surgery, or arthroplasty. Surgical site infections remain a critical and frequent complication of surgical treatment of soft-tissue malignancies and often result in prolongation of hospital stay. Although practical options to prevent surgical site infections seem quite limited, the present data provide a rationale for perioperative evaluation in patients at a high risk of surgical site infections.

D-dimer levels as a prognostic factor for determining oncological outcomes in musculoskeletal sarcoma

BackgroundPlasma d-dimer levels have been associated with the status of tumor progression or oncological outcomes in cancer. Although there are many evidences suggesting the involvement of procoagulant trend in musculoskeletal sarcoma, no clinical data on d-dimer levels and oncological outcome of musculoskeletal sarcoma has been reported.MethodsIn this study, we included a total of 85 patients who were diagnosed with musculoskeletal sarcoma and treated at our institute. Plasma d-dimer levels were determined before performing any clinical intervention, including open biopsy, chemotherapy, radiotherapy or tumor resection. We evaluated the effect of d-dimer levels and other clinicopathological factors on oncological outcomes of patients.ResultsUpregulation of plasma d-dimer levels proved to be an independent risk factor for metastasis and lethal outcome of patients with musculoskeletal sarcoma.ConclusionsUpregulation of plasma d-dimer levels were indicated poor oncological outcome in metastasis and total survival rate of musculoskeletal sarcoma patients. Hence d-dimer levels may be a helpful marker for evaluating the tumor progression status and prognosis of musculoskeletal sarcoma.

Anterior lumbar interbody fusion: changes in area of the dural tube, disc height, and prevalence of cauda equina adhesion in magnetic resonance images.

Objective: Many investigators have reported satisfactory outcome in anterior lumbar interbody fusion (ALIF) performed for lumbar disc herniation or “multiply operated back” (MOB), but without comparing preoperative and postoperative dural tube area and cauda equina adhesion in magnetic resonance imaging (MRI). We conducted this study to determine these data in ALIF performed for lumbar disc herniation and MOB. Methods: Thirty-two patients who underwent ALIF, involving 38 discs, were studied. In MRI obtained before and after surgery (interval 9–48 months, mean 19.2 months), cross-sectional areas of the lumbar dural tube were measured from axial T2-weighted images using a computer-linked digitizer. At 30 disc levels operated on, the cauda was identified in images; cauda equina adhesions were classified according to Matsui et al (grade I–III). Clinical improvement was scored. Results: Bony union was observed in radiographs of all patients. Preoperative and postoperative cross-sectional areas of the lumbar dural tube were 1.32 ± 0.4 and 1.87 ± 0.5 cm2, respectively, and expansion ratio was 1.43 ± 0.4. Recovery did not correlate with expansion ratio. Positive correlation was noted between expansion ratio and disc height ratio. At 30 disc levels where cauda equina was identified, 22 represented grade I and 8 represented grade II. At three of the latter, prior surgery had been performed via a posterior approach. Conclusions: No significant difference was noted in occurrence of grade II adhesions between primary ALIF and ALIF performed for MOB. Dural tube expansion was accomplished even without exposure of the tube, and cauda equina adhesion was uncommon in primary ALIF.